The need to power electronics equipment, communications gear, medical devices and other equipment in remote field service has been on the rise in recent years, increasing the demand for highly efficient, mobile power systems. These applications require power sources that provide both high power and energy density, while also requiring minimal size and weight, low emissions and cost.
To date, batteries have been the principal means for supplying portable sources of power. However, due to the time required for recharging, batteries have proven inconvenient for continuous use applications. Moreover, portable batteries are generally limited to power production in the range of several milliwatts to a few watts and thus cannot address the need for significant levels of mobile, lightweight power production.
Small generators powered by internal combustion engines, whether gasoline- or diesel-fueled have also been used. However, the noise and emission characteristics of such generators have made them wholly unsuitable for a wide range of mobile power systems and unsafe for indoor use. While conventional heat engines powered by high energy density liquid fuels offer advantages with respect to size, thermodynamic scaling and cost considerations have tended to favor their use in larger power plants.
Photovoltaic and thermoelectric generators are the only commercially available energy conversion technologies below 2 kilowatts. While the benefits of photovoltaic are clear, the drawbacks are obvious. With respect to thermoelectric generators, they tend to be large, expensive and relatively inefficient.
In view of these factors, a void exists with regard to power systems in the size range of approximately 50 to 2000 watts. Moreover, in order to take advantage of high energy density liquid fuels, improved fuel preparation and delivery systems capable of low fueling rates are needed. Additionally, such systems must also enable highly efficient combustion with minimal emissions. A quiet, clean power source below 2 kilowatts could advantageously supplement current technologies, such as those based on photovoltaic arrays, and yield an advantageous hybrid system for generating electrical power.